Can you tell me how you figured out the other filenames? That’s something I tried to do a long time ago for another project, and could never figure out.

Looked in my Internet Explorer cache folder and saw a file called "level23" hanging around.

Also, by chance, their web server happens to have a feature that offers you a similar file name if you get it close. For example, if I tried to open a file from that folder called "level23.dat", a convenient page comes up offering me level23.txt, instead of a plain-old 404. That's how I found the config.txt file.